Process for purifying or refining metals and alloys



1,636,881 J 1927' D. R. TULLIS PROCESS FOR PURIFYING 0R REFINING METALS AND ALLOYS Filed NOV. 9. 1926 Patented July 26, 1927.

rrica DAVID RONALD TULLIS, OF CLYDEBANK, SCOTLAND.

PROCESS FOR PURIFYING OR REFINING METALS AND ALLOYS.

Application filed November 9, 1926, Serial No. 147,227, and in Great Britain November 11, 1925.

This invention relates to a process of purifying or refining aluminium and its alloys while in the molten state to remove therefrom dissolved gases or other impurities.

The invention consists in introducing into the molten metal or alloy a gas containing chlorine, namely boron trichloride.

In practice chlorine gas is led through a desiccator and thence through a tube located within a furnace andcontaining boron trioxide and carbon, so that there issue from the tube boron trichloride and carbon monooxide, whence the mixture passes through an ahsorhent tor the carbon monoxide, and

the boron trichloride is led into a molten hath ol aluminium alloy in which is a stirring device. As the gas is liberated in the bath. the boron passes into alloying relation with the aluminium and the chlorine expels the gases contained in the alloy with the subsequent formation of aluminium chloride which rises to the top'ot the bath.

\Vhen it is ascertained that dissolved gases and/or other impurities are removed, the

2 metal or alloy may be transferred to moulds for the production of castings.

The figure of the accompanying drawing illustrates a simple form of apparatus suitable for the performance of the process.

As shown, 1 denotes a bottle charged with 3|) dry chlorine gas which is led from the hottle through a tube 2 located within a furnace I3 and containing say boron trioxide and carbon. so that there issue from the tube 2 boron trichloride and carbon monoxide, whence the mixture passes to the vessel 4 containing an absorbent for the carbon monoxide. From the vessel 4 the boron trichloride is led to the crucible 5 containing a molten charge of aluminium alloy by way of a tube 6 of silica 4o opcratively connected by gearing to a motor 7 :0 that the tube may function as a stirrer. As'thc gas is liberated in the hat-lathe boron passes into alloying relation with the aluminium and the chlorine expels the gases 4 contained in the alloy with the subsequent formation of aluminium chloride which rises to the top.

I claim A process of 'mrit'ying or reliniug aluminium and its alloys consisting in introducing into the metal or alloy boron trichloride.

ln testimony whereof I have igned my name to this specification.

DAVID RONALD TULLIS. 

